one of the biggest threats to the future existence of mankind. As one of the world’s largest food sources and environmental stabilisers, if the ocean dies, then the earth we know goes with it. Most ocean pollution begins on land with unsustainable human activities. Some forms of contamination, such as the Great Pacific Garbage Patch in the Pacific Ocean, are well known and publicised. However, pollution comes in a range of visible and invisible forms which all need to be treated with equal urgency and care.
Here are some marine pollution facts which most people are unaware of:
One of the biggest sources of pollution is called nonpoint source pollution. It occurs as a result of contaminated runoff after rainfall, and comes from things such as septic tanks, vehicles, farms, and forest areas. When this contaminated water reaches the ocean, it harms delicate ecosystems and causes unmeasurable damage¹.
Oil spills only account for around 12% of all oil which enters our oceans. Over 35% comes from runoff, and another 22% comes from tanker operations².
For years the ocean has been a convenient dumping point for toxic chemical waste. Although the London Dumping Convention of 1972 restricted what can be dumped at sea, there is still an unsustainable amount of toxins entering the marine environment³.
One of the least obvious aquatic pollutants is Carbon Dioxide (CO2). Since the Industrial Revolution, mankind has been spewing huge quantities of CO2 and other greenhouse gases into the atmosphere. From there, they dissolve in the ocean and cause huge problems including ocean acidification and rising water temperatures. This is extremely harmful to corals, shellfish, and other organisms as it reduces their ability to form their solid shells or exoskeletons⁴.
Radioactive waste has caused huge problems for marine life following the Fukushima nuclear power plants toxic waste leaks. Since the disaster, millions of litres of radioactive water have leaked into the sea, where it is affecting marine organisms as far away as the west coast of North America⁵. Although there is little concrete evidence, there are theories that this radiation has led to the mass deaths of a variety of animals in the western Pacific Ocean, including seabirds, dolphins, and seals.
Most of the Great Pacific Garbage Patch is actually small, microscopic plastic beads. These are extremely harmful to all marine life, but especially to plankton feeders such as some whales⁶.
Marine pollution has a vast range of effects, many of which are invisible to the untrained eye. For example, pathogens from sewerage and untreated waste can return to the food chain through fish and shellfish and spread disease and illness when consumed⁷.
Nutrients from fertilizers and sewerage can cause algal blooms which deplete the water of oxygen. This can cause mass fish kills and displace marine organisms⁷.
Noise pollution from large ships and machinery can disrupt many aquatic animals, particularly mammals. Large cetaceans such as whales can become obviously distressed when there is too much background noise, as it can interfere with their communication and navigation systems⁷.
It is clear that we must clean up our act and stop polluting the oceans with the by-products of our luxurious lives. If we continue to disrespect nature and use it as our personal garbage tip, then the world is set to change for the worse, likely within decades.